package cn.itcast.dewu.utils;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Component;

import java.time.LocalDateTime;
import java.time.ZoneOffset;
import java.time.format.DateTimeFormatter;

@Component
public class RedisIdWork {
    //开始的时间戳
    private static final long BEGIN_TIMESTAMP = 1641040200L;
    //序列号位数
    private static final int COUNT_BITS = 32;

    @Autowired
    private StringRedisTemplate redisTemplate;

    //id生成器
    public long nextID(String keyPrefix) {
        //生成时间戳
        LocalDateTime now = LocalDateTime.now();
        long nowSecond = now.toEpochSecond(ZoneOffset.UTC);
        long timestamp = nowSecond - BEGIN_TIMESTAMP;

        //生成序列号
        String date = now.format(DateTimeFormatter.ofPattern("yyyy:MM:dd"));
        //自增长
        Long count = redisTemplate.opsForValue().increment("icr:" + keyPrefix + ":" + date);

        //拼接并返回
        return timestamp << COUNT_BITS | count;
    }

    public static void main(String[] args) {
        LocalDateTime time = LocalDateTime.of(2022, 1, 1, 12, 30);
        long l = time.toEpochSecond(ZoneOffset.UTC);
        System.out.println(l);
    }
}
